Boiler furnace



J; B. CRANE BOILER FURNACE May 27, 1930.

2 Sheets-Sheet 1 Filed Feb. 17-, 1926 y 1930- I J. B. CRANE I 1,760,118

BOILER FURNACE Filed Feb. 17, 1926 2 Sheets-Sheet 2 IN VEN TOR Maw / 6(I +1: 4 L Warming Patented May 27, 1930 UNITED STATES PATENT OFFICEJ'OSELPfi B. CRANE, OF IITTSBUEGH, PENNSYLVANIA, ASSIGNOR TO LADD WATERTUBE BOILER COMPANY, OF NEW YORK, N. Y., A CORPORATION OF DELAWAREBOILER FURNACE Application filed February 17, 1326. Serial No. 88,762.

This invention relates to boiler furnaces and is especially useful wherethe fuel to be burned is in finely divided form, such as pulverizedcoal.

One of the primary objects of the invention is to greatly increase thecapacity of a boiler of the type having substantially horizontal banksof tubes without materially increasing the size of the installation.

By my invention I propose by a novel arrangement of a boiler of theabove character and a combustion chamber therefor to convert an ordinaryinstallation of this type into a high capacity boiler installation, orto construct a new installation from parts heretofore used inconstructing the standard form of boilers of this class.

The invention is particularly useful, although not necessarilyrestricted to, the conversion of Babcock and Wilcox boilers inconnection with which it will be described.

Another object of my invention is the provision of a novel arrangementof water tubes for use as a water wall of a combustion chamber.

Still another object of my invention is to provide a novel arrangementwhereby the degree of superheat may be readily controlled.

A more specific object is to provide a novel arrangement of the watertubes forming the sides of the combustion chamber whereby burneropenings are afforded without very materially reducing the tube surfacesexposed to radiant heat. A

Other objects and advantages of my invention will be set forthhereinafter as they will be more readily understood in connection withthe description of the invention.

How the foregoing, together with such other objects as may be incidentto my invention, are realized is illustrated in preferred form in theaccompanying drawings wherein Fig. 1 is a vertical section thru aboilerfurnace embodying the preferred form of my invention;

Fig. 2' is a plan section taken on the line 2-2 of Fig. 1;

Fig. 3 is a similar plan section to that of Fig. 2 showing a modifiedburner arrangement;

Figs. 4 and 5 are enlarged fragmentary views showing modifiedarrangements of the side wall tubes;

v Figs. 6 and 7 are plan sections taken on the line 66 and 7-7 of Figs.4 and 5 respectively;

Fig. 8 is an enlarged fragmentary view showing a modified arrangement ofend wall tubes; and

Fig. 9 is a plan section taken on the line 9-9 of Fig. 8.

Referringto the drawings and particularly to Fig. 1 in which I haveshown how my invention would be carried out in connection with a boilerof the cross drum type having two banks of substantialv horizontalboiler tubes A and B, it will be seen that I preferably drop the bank oftubes B and their headers a sufiicient distance to provide adequatespace for a combustion chamber 0 therebetween.

The side and end walls of the combustion chamber are defined by wallsformed of evaporating elements connected for circulation as will furtherappear. As shown in Figs. 1,2 and 3 the side walls 10 and 11 'comprise aplurality of finned tubes 12 preferably vertically arranged andconnected to the upper and lower headers 13 and 14 respectively. The endwalls 15 and 16 each comrise a plurality of finned tubes 17, the tubes 7of one wall being connected to the headers 18 of the upper bank of tubesA and to the headers 19 of the lower bank of tubes B, and the tubes 17of the other wall being connected to the headers 20 of the upper bank oftubes A and to the headers 21 of the lower bank of tubes B; and aplurality of other finned tubes 22 connected to cross headers 23 and 24.The tubes 22 are shown as being shorter than the tubes 17 and are bentoutwardly at their ends for connection to the headers 23 and 24 outsidethe combustion chamber. Furthermore, it will be seen that these tubes 22are so positioned with respect to the tubes 17 that aplurality ofopenings 25 are provided, between certain of the tubes 17 and in thelower portion of the walls of the other end wall are similarly connectedto the drum 27. The tubes 17 of these walls, as before mentioned,connect the upper and lower headers of the vertical rows of tubes of thebanks of tubes A and B, which headers may be either straight or sinuous,the upper means of the finned downcomer tubes 30 and I the upper headers20 being connected to the drum 27 by means of the u comer tubes 31. Thusit will be seen that the ow is downward through the tubes 17 of the wall16 and upward through the tubes 22 thereof. The flow through the tubesof the end wall 15 is upward.

The lower headers 14 of the-side walls 10 and 11 are connected to thedrum 27 by means of downcomer pipes 32 and the upper headers 13 thereofare connected to said drum by means of upcomer pipes 33, thus the How isupward through these side tubular walls.

Fuel, such as pulverized coal, and air are introduced to the boilerfurnace through the burners 26 which are shown in Fig. 2 as beingoppositely disposed. and in this instance 1ying in an inclined plane, byvirtue of which the fuel streams will impinge, causing turbulentcombustion. As a further aid in causing turbulent combustion, theburners may be disposed in staggeredrelation as indicated in Fig. 3.Preheated combustion air may be admitted with the fuel, which air may beheated by a suitable heater in the stack, whereby the coal and highlypreheated air produce an intensely hot flame practically filling thecombustion chamber Withthe exception of in the region of the burners.Hence the furnace temperature head is increased, and since thecombustion chamber is defined by evaporating elements exposed to radiantheat, there is a very rapid transfer of heat.

The products of combustion are drawn through the banks of tubes A and Bunder the influence of the stack draft, there bemg a damper controlledofitake D above the bank of tubes A and a damper controlled ofl'take Ebelow the bank of tubes B. In the particular arrangement shown in thedrawings I have indicated a superheater F located between the upper bankof tubes A and the offtake D. the degree of superheat of which maybecontrolled by manipulation of the dampers. More specifically stated,the upper damper would be preferably kept full open and the lower one.regulatedto control headers 18 being connected to the drum 27 by stoodthat the superheater may be located below the lower bank of tubes, inwhich case the lower damper would be preferably kept full open and theupper one regulated to control the amount of gas passing through theupper bank of tubes.

Referring now to the modification shown in Figs. 4 and 6, I have shown awall con-' struction comprising a pair of superimposed upper headers 34and 35, a pair of superimposed lower headers 36 and 37 and a plurahty ofclosely adjacent tubes 38, alternate ones of which are connected to theheaders 35' and 36. By this, employment of double upper and lowerheaders, I am enabled to have the tubes substantially abut and havesufficiently strong ligaments in the headers. In Figs. 5 and 7 I haveshown another modified form of tubular wall structure in which thatportion of the tubes exposed to radiant heat is arranged in twodifferent planes which. in effect, provides a double water wall asindicated at 39, whereby a-maximum of heat absorbing surface is exposedto the.

chamber.

In Figs. 8 and 9 I have shown how the arrangement of Figs. 4 and 6 couldbe applied to the end walls of the boiler-furnace described, the tubesbetween the headers of the banks of tubes being indicated by thereference numeral 17 and the shorter tubes by the numeral 22*.

It is understood that any suitable form of sheathing for theboiler-furnace such as that shown may be employed. 7

The boiler is capable of developing a very high capacity and very highratings in comparison to present practice, and it will also be seen thatthe boiler-furnace is one that is well adapted to be operated at apositive pres-- sure whereby combustion is speeded, and it is possibleto make the combustion space of relatively small size.

I claim:

1. .The combination with a boiler of the type including verticallyspaced banks of substantially horizontal water tubes and their headers,of a combustion chamber intermediate the levels of said banks of tubes,said combustion chamber being defined by said banks of tubes and byvertical water tubes,

.mcans for introducing fuel to be burned in suspension therein, and anofitake for the products of combustion beyondv each of said banks oftubes, a superheater located between 2. The combination with a. boilerof the type including vertically spaced banks of substantiallyhorizontal water tubes and their headers, of a combustion chamber intemediate the levels of said banks of tubes, said combustion chamber beingdefined by said banks of tubes and "by vertical water tubes, means forintroducing fuel to be'burned in suspension therein, a damper controlledofl'take for the products of combustion beyond each of said banks oftubes, and a superheater located between one of said banks of tubes andthe ofl'take therebeyond.

3. The combination with a boiler of the type including vertically spacedbanks of substantially horizontal water tubes and their headers, of acombustion chamber intermediate the levels of said banks of tubes, saidcombustion chamber being defined by said banks of tubes and by verticalwater tubes, means for introducing fuel to be burned in suspensiontherein, an ofl'take for the products of combustion beyond each of saidbanks of tubes, a superheater located between one of said banks of tubesand the offtake therebeyond and means for controlling of tubes intowhich the ends of the tubes are connected, upright tubes connecting thefront headers of the banks of tubes, upright tubes connecting the rearheaders of the anks of tubes, an upper steam and. water drum,

said upright tubes, and the sides by tubular water walls having upcomerand downcomer connection with the steam and water drum, and means forintroducing fuel to be burned in suspension in said combustion space.

In testimony whereof I- have hereunto signed my name. I JOSEPH B.CRANE.

tubes, relative to the amount passing over the other bank of tubes.

4. The combination with a boiler of the type including vertically spacedbanks of substantially horizontal water tubes and their headers, of acombustion chamber interme-,

diate the levels of said banks of tubes, said combustion chamber beingdefined by said type including vertically spaced banks of substantiallyhorizontal water tubes and their headers, said banks of tubes howeverbeing substantially separated to provide a combus- I tion spacetherebetween; of upright water tubes marginal of the sides of saidcombustion space; upper and lower headers for said water tubes; uprightwater tubes marginal of the ends of said combustion space, said lastmentioned water tubes being connected into the headers of the aforesaidbanks of tubes; other upright water tubes marginal of the ends of saidcombustion chamber; other upper and lower headers for said lastmentioned water tubes; upcomer and downcomer means connecting the lastmentioned tubes into the circulation of the boiler; upcomer anddowncomer means connectin the side tubes into the circulation of the boier; means 'for admitting fuel and air into said combustion space; and anofi'take for the products of combustion.

' 6. In combination, a boiler of the horizontal type having verticallyspaced banks of tubes, front and rear headers for each bank

